TY - JOUR
T1 - Heat and fluid flow in additive manufacturing – Part II
T2 - Powder bed fusion of stainless steel, and titanium, nickel and aluminum base alloys
AU - Mukherjee, T.
AU - Wei, H. L.
AU - De, A.
AU - DebRoy, T.
N1 - Funding Information:
We acknowledge the support from the US Department of Energy Nuclear Energy University Program grant number DE-NE0008280 . One of the authors acknowledges support of an American Welding Society research fellowship, grant number 179466 . We also acknowledge helpful discussions with J.S. Zuback and G.L. Knapp of Penn State University.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/7
Y1 - 2018/7
N2 - The most important metallurgical variables that affect the structure and properties of components produced by powder bed fusion (PBF) are examined using a model, proposed and validated in part-I of this paper. These variables include the temperature and velocity fields, build shape and size, cooling rates, solidification parameters, dendrite arm spacing, hardness, distortion and lack of fusion defects for four common alloys used in additive manufacturing (AM), stainless steel 316 (SS 316), Ti-6Al-4V, Inconel 718 and AlSi10Mg. The process parameters examined include laser power, scanning speed, powder layer thickness, packing efficiency and hatch spacing. Among the four alloys, the largest molten pool of AlSi10Mg ensures good fusional bonding among layers and hatches but exhibits high solidification shrinkage. Therefore, AlSi10Mg is the most susceptible to distortion among the four alloys. SS 316 exhibits the opposite trend because of its smallest molten pool among the four alloys. For a particular alloy, lack of fusion and distortion can be minimized by careful selection of hatch spacing and scanning speed. For the dendritic growth of SS 316 and AlSi10Mg, refinement of the solidification microstructure through close spacing of the dendrite arms can be achieved using thinner layers and faster scanning. Asymmetry in liquid pool geometry because of the difference in the thermal properties of powder bed and solidified build can be minimized by reducing the scanning speed.
AB - The most important metallurgical variables that affect the structure and properties of components produced by powder bed fusion (PBF) are examined using a model, proposed and validated in part-I of this paper. These variables include the temperature and velocity fields, build shape and size, cooling rates, solidification parameters, dendrite arm spacing, hardness, distortion and lack of fusion defects for four common alloys used in additive manufacturing (AM), stainless steel 316 (SS 316), Ti-6Al-4V, Inconel 718 and AlSi10Mg. The process parameters examined include laser power, scanning speed, powder layer thickness, packing efficiency and hatch spacing. Among the four alloys, the largest molten pool of AlSi10Mg ensures good fusional bonding among layers and hatches but exhibits high solidification shrinkage. Therefore, AlSi10Mg is the most susceptible to distortion among the four alloys. SS 316 exhibits the opposite trend because of its smallest molten pool among the four alloys. For a particular alloy, lack of fusion and distortion can be minimized by careful selection of hatch spacing and scanning speed. For the dendritic growth of SS 316 and AlSi10Mg, refinement of the solidification microstructure through close spacing of the dendrite arms can be achieved using thinner layers and faster scanning. Asymmetry in liquid pool geometry because of the difference in the thermal properties of powder bed and solidified build can be minimized by reducing the scanning speed.
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U2 - 10.1016/j.commatsci.2018.04.027
DO - 10.1016/j.commatsci.2018.04.027
M3 - Article
AN - SCOPUS:85045627477
VL - 150
SP - 369
EP - 380
JO - Computational Materials Science
JF - Computational Materials Science
SN - 0927-0256
ER -